256 THE ZOOLOGIST. 



history of the Plaice does not seem to suggest it. It is possible, 

 from the observations of Dr. Wallace on the ear-bones and other 

 points in this fish, that its average rate of growth is higher in 

 offshore than in inshore grounds. Experience would seem to 

 show that there is little fear of suitable ground being left un- 

 occupied by such fishes as Plaice. 



The third head — viz. the intensity of trawling in the North Sea 

 — as indicated by the capture of the marked Plaice, is apparently 

 considered an important discovery by the staff of the Marine Bio- 

 logical Association. In all about 900 marked Plaice were liberated 

 in the offshore and about 563 in the inshore grounds, the per- 

 centage captured in the former being twenty and in the latter ten in 

 twelve months, it being explained that fewer captures take place 

 in the inshore grounds when trawling is prohibited. The Asso- 

 ciation, therefore, considers that " from this result it seems clear 

 that the total annual catch of the fishermen no longer forms an 

 insignificant proportion of the total stock of Plaice." In short, 

 fishing would thus appear no longer to be an uncertain pursuit 

 in the hands of the Association. 



But, as pointed out in the first lecture, this conclusion is not 

 supported by fifty years' scientific experience of the Bay of St. 

 Andrews, a bay which contains no spawning Plaice, which are 

 in the open waters beyond, free to every trawler, nor does it 

 appear to coincide with the history of the Plaice-fishery of the 

 Cattegat. Again, in the old trawling days of nearly a quarter of 

 a century ago, it was not uncommon to bring on board the dead 

 Frog-fishes (usually with a slit on the under surface), and old 

 utensils of other trawling-ships on well-known grounds, and, 

 though this showed considerable intensity of fishing, yet the 

 same grounds are regularly fished to-day in their season. There 

 are various degrees of intensity of fishing ; thus, though Salmon, 

 Green-Cod, Greenbones, and other forms occasionally abound off 

 our shores, yet they seldom appear in the trawl. As already 

 shown, fixed gill-nets for Cod and Plaice make us acquainted 

 with various forms (Sharks, Porpoises, Sturgeons) rarely met 

 with in the trawl or on the lines. 



Besides, the numbers dealt with are too few for a conclusion 

 so important, and there is considerable difference of opinion 

 amongst the international observers themselves. It would seem 



